Total arsenic was detected in 37 meconium samples (38.5%) with a range of 0.10 to 31.40 ng/g of meconium. The mean (SD) and geometric mean concentration of total As were 6.79 (1.05) ng/g and 4.55 ng/g, respectively. Percentiles were determined at 5th: 0.40 ng/g, 25th: 3.0 ng/g, 50th: 5.60 ng/g, 75th: 7.4 ng/g and 95th: 25.50 ng/g. [Range: 0.01 to 2.49 ng/ml (ppb); Mean (SD): 1.05 (0.13) ng/ml (ppb); Geometric mean 0.62 ng/ml (ppb); Percentiles at 5th: 0.03, 25th: 0.28, 50th: 0.76, 75th: 1.77 and 95th: 2.30 ng/ml (ppb)].
Tenerife Island is divided into 3 areas; metropolitan, north and south areas. In the south area the meconium samples positive for arsenic were less frequent (detected As 27.6% vs non-detected As 43.5%) than in the metropolitan area (51.7% vs 45.7%) or the north area (20.7% vs 10.9%). The differences between the areas were not statistically significant (p
0.285). Furthermore, Santa Cruz de Tenerife city, the main municipality in the metropolitan area, has 5 districts. The majority of samples with arsenic detected were in Centro-Ifara district with the old quarter and Port of Santa Cruz (detected As 45.5% vs non-detected As 5.9%),. The frequency of positive meconium for As was lower in the following 3 districts which are mainly residential areas: Ofra-Costa Sur (detected As 9.1% vs non-detected As 5.9%), Salud-La Salle (18.2% vs 41.2%) and Sudoeste (27.3% vs 47.1%). The differences observed did not reach statistical significance (p
Finally, there were no meconium samples collected from Anaga district, a rural and mountainous profile area.
The distribution of parental sociodemographic characteristics in the two categories: As detected and As non detected is shown in . More than 85% of mothers were Spanish. In the category of newborns with detectable arsenic levels, 34.6% were offsprings of mothers with advanced university degree compared to 4.3% in the category of newborns without detectable arsenic levels in meconium (OR: 12.0; CI (95%): 2.16–66.55); secondary education was taken as reference category. In addition, fewer newborns have been exposed to arsenic when the father’s social class was managerial or technical (15.4% vs 31.0%; OR: 0.09; CI (95%): 0.01–0.61) and partly skilled (30.8% vs 47.6%; OR: 0.11; CI (95%): 0.02–0.67); skilled category was taken as the reference.
Parental socio-demographics characteristics by prenatal exposure to total arsenic detected in meconium.
Children with detectable levels of arsenic had a significantly higher birth weight compared to the children without detectable As (OR: 1.00; CI (95%): 1.00–1.02). No other obstetric and perinatal outcomes were significantly associated with arsenic in meconium ().
Obstetric and anthropometric characteristics of the newborns according to the results obtained.
Maternal lifestyle, chemical exposure and dietary habits during pregnancy are presented in . Newborns with As in meconium were less exposed to tobacco smoke, due to the fact that no mother in that category smoked during pregnancy and fewer mothers were exposed to second hand smoke (OR: 0.16; CI (95%): 0.03–0.80).
Maternal lifestyle, chemical exposure and dietary habits during pregnancy.
The source of mother's water for consumption does not appear to be a determining factor of arsenic exposure. Conversely, a frequent intake of vegetables was associated with prenatal exposure to arsenic (OR: 1.19; CI (95%): 1.01–1.41). A frequent intake of processed meat (as bacon, Frankfurt’s sausage, and hamburger) was associated with As in meconium but that association did not reach statistical significance (CI (95%): 0.80–90.89). On the other hand, low weekly intake of eggs was associated with prenatal exposure to arsenic (OR: 0.56; CI (95%): 0.34–0.94).
shows the OR and 95%CI obtained in the unadjusted and adjusted logistic regression model. This model includes only the statistically significant variables from the univariate logistic regression model.
Multivariate regression model.
Maternal average intake of vegetables during pregnancy was the single factor significantly and independently associated with prenatal exposure to As by meconium analysis in our study.
Arsenic concentration in meconium was significantly correlated only with average consumption of white meat (Spearman’s rho: −0.45; p
0.02). However, it was not significantly correlated with average consumption of vegetables (Spearman’s rho: 0.02; p
0.90), eggs (Spearman’s rho: −0.22; p
0.25) and processed meat (Spearman’s rho: 0.63; p